Objective:To establish and evaluate a mouse model of graded Allen’s spinal cord injury(SCI)

and provide theoreti- cal evidence for a new model of contusive SCI. Methods:A total of 171 mice were divided into surgical controls(n=18)that received laminectomy but did not receive a contusive injury

and experimental groups(n=153)ruined by modified Allen’s method and distinguished by the amount of weight in grams dropped onto the impounder and height from the weight to the impounder: group A(1 g × 2.5 cm n=18)

group B(2 g × 2.5 cm n=45)

group C(3 g × 2.5 cm n=45) and group D(3 g × 5 cm n= 45).All animals were assessed by electrophysiological

structural and examined using the basso mouse scale(BMS). Results:Ax- cept the group A

the BMS revealed a statistically significant difference between surgical controls and experimental groups after injury. In experimental groups

both initially and as recovery progressed over time

there was no difference in functional outcome between group B and surgical controls at 2 week;group D recovered badly with a high mortality and there was no recovery evidence in group C up to 8th week. The mean peak latency of N1 wave in MEP prolonged within 3days and then gradually decreased in experimental groups;however

by 1 week there was no significant difference between group B and surgi- cal controls(P>0.05); in group C and D

there were still significant difference at 8 weeks. there were different histopatholog- ical changes in groups during the test. Conclusion:A mouse model of contusive spinal cord injury is a reasonable model and provides theory basis for SCI studies.